This is strange to me, and I'm thinking it sounds like power output is suffering. My '77 with turbo swap, 4-speed, and 3.07 rear end has zero trouble with getting up to speed on steep hills. Even at 700 RPM idling, I can let the clutch out on milder inclines without giving any throttle, and the car starts moving without effort. There is a bit more delay in boost kicking in on slopes, but I have never had a fear of not making it up any steep hill, even though there have been a few that were so steep and gravel/dirt covered that traction became a real issue.

It seems to me like either my car is a freak, or your car isn't putting down the low-end power that it should, over-sized tires, or not. What is the service history of your motor? Maybe it's the 2.88 rear end, but I'd exhaust the tuning options before doing gear swap. Having experienced a few gear ratios, and many underpowered 617's, I can't see the 2.88 becoming that much of a disadvantage. It's usually the motor that is the issue.

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- K.C.Adams

'77 300D Euro Delivery
OM617 turbo / 4-speed swap
404 Milanbraun Metallic / 134 Dattel MB-Tex

Current status:
* Undergoing body work

My '77 300D progress thread